I don't know what ball lightning is, but I did see one once while in the service. We were inside during a Florida thunderstorm, as it was winding down. My buddy said, "Look at that! Look at that!" His excitement drew me to the glass door from where I saw a glowing ball sitting on the roof of his car, parked about 30 yards (meters) away. The ball was between one-half to one meter in diameter, reddish orange on the fringes, the color transitioned through the spectrum to a dark blue in the center. The diameter of the the bluish center was maybe one third the overall diameter. The ball seemed to roll very slowly to the back of the roof, then quickly down the back window then slowly down the trunk lid to the edge where it dropped off and dissipated on the asphalt. The ball did not change size appreciably until it dissipated. This took about 5 seconds all together. The ball dissipated quickly, but not instantaneously, maybe a few (2 - 4) tenths of a second.

Very soon thereafter, we went out and looked for damage to his car and the paint. There was no discernible damage and in fact, nothing out of the ordinary.

Regarding the movement of this lightning ball; it moved much as you would expect a rubber balloon to move. Slowly down the sloping roof and trunk lid and more quickly off the edges. The lot was graded so cars parked with the front 2- 4 inches higher than the back, hence the slope.

These people claim to create plasmoids stable in air (but not vacuum) and that this is how ball lightning works. It seems plausible to me, since we know ball lightning does exist.

They also hope to collide plasmoids at high speed to do fusion. This is less sensible. For one thing the plasmoids are only stable in air but (presumably) losses accelerating them to high energies would be very high except in near vacuum.